The International Energy Conservation Code (IECC) is the most commonly adopted model energy code for residential buildings. It is updated every three years, with the most recent version being the 2012 IECC. These guides help determine what the IECC requirements for each state and county would be under each version of the code. These guides do not include any state-specific or local amendments and do not necessarily reflect the actual code adopted in your jurisdiction. They are not intended to be an official compliance tool, unless your local code official has approved them as an acceptable method of compliance. In addition, note that these guides do not address commercial building requirements.

The Building Codes Assistance Project (BCAP) tracks the status of the building energy codes adopted in states or local jurisdictions. Check with BCAP to determine the specific code that applies to your location. If your local or state code is based on the IECC without amendments regarding windows, select the appropriate code fact sheet from the table below.